Digital printing inks are similar to other inks and paints. All of these products consist of two basic components: a colorant (dye or pigment) and a liquid carrier or vehicle. The varieties of digital printing inks include aqueous inks, solvent inks, Eco-solvent inks, latex inks and UV-curable inks. With so many choices available in wide format printing, considerations in ink selection include compatibility with the substrates, application, durability, brightness of color and cost.
If an application requires longevity, pigment inks are much more durable than dye-based inks. Those pigments that that fade after a short period of time are referred to as “fugitive colors”. While pigments are viewed a producing less vibrant images, improvements in ink technology has expanded the color gamut. For outdoor applications, such as vehicle graphics and outdoor advertising, pigmented inks are usually preferred.
In the digital printing field, pigment inks, however, have been associated with metameric color shifts. Advances in ink formulation have reduced many of the problems associated with metamerism. Dye-based inks, by comparison are less metameric.
The advantage of a dye-based ink is its bright colors. For this reason, these inks were selected for indoor applications, such as P.O.P. posters and displays and photographic prints. The downside of dye-based ink was that you sacrificed durability. While fade resistance has improved greatly with new color formulations, the more vibrant dye-based inks generally exhibit a much lower resistance to UV light.